Worldly bishop stops youth taking drug (7)
I believe the answer is:
terrene
'worldly' is the definition.
(thesaurus)
'bishop stops youth taking drug' is the wordplay.
'bishop' becomes 'rr' (abbreviation for Right Reverend).
'stops' means one lot of letters goes inside another.
'youth' becomes 'teen' (I've seen this before).
'taking' is a charade indicator (letters next to each other).
'drug' becomes 'e' (e is another name for ecstasy).
'rr' inserted within 'teen' is 'terren'.
'terren'+'e'='TERRENE'
(Other definitions for terrene that I've seen before include "unearthly? The opposite" , "Earthy" , "Of the earth, worldly" , "Earthly" , "region" .)